The invention relates to an implantable medical device and a method for the control of fluid flow through a body host canal or vessel, such as a urethra.
Incontinence is a condition wherein persons lose control over their voluntary urinary function. The condition can arise from various causes, which include a variety of related and unrelated diseases, aging, and deterioration of the voluntary urethra sphincter muscle. The cost and inconvenience to persons suffering from this condition are great. Several remedies exist that are known in the prior art. Among these, the most common are surgical corrections both minor and major, drugs, devices and diaper capture systems which serve to capture discharges. Another solution is to place a patch over the urinary orifice to prevent unwanted discharge. Possibly, the most effective solution to date is the use of an artificial sphincter. This device is surgically installed and is hydraulically or pneumatically driven, operating by inflation of ballasts to suppress fluid flow. However, control of this device is sometimes difficult and is often inconvenient. Throughout the full range of the available treatment alternatives, the levels of efficacy, useful life, and complications vary greatly, with none of the current treatment alternatives being particularly effective in especially severe cases. Accordingly, there is a need for an improved apparatus to control the loss of voluntary urinary function.
The present invention overcomes and alleviates the above-mentioned drawbacks and disadvantages in the art through novel implantable body fluid flow control devices for the control of fluid flow through a host body canal or vessel, such as a urethra.
Generally speaking, and in accordance with a first aspect of the invention, an implantable apparatus for controlling fluid flow within a host body comprises a constricting member for allowing fluid flow within a body canal when in an open position and for reducing fluid flow within a body canal when in a closed position, an actuating member for operating the constricting member between said open and closed positions, and control means for operating said actuating member.
Preferably, the constricting member comprises a first engaging element and a second engaging element for coupling to the first engaging element to encircle a body canal. At least one of the first engaging element and the second engaging element preferably has apertures to allow tissue growth therethrough from and to the surface of the body canal. A locking member is preferably provided for locking the first engaging element and second engaging element into the locked position.
The constricting member preferably comprises a plunging member moveable such that the plunging member may apply pressure against said body canal to compress said body canal into said closed position. The actuating member preferably comprises a connector having first and second ends. The first end of the connector is preferably attached to said plunging member and is axially moveable by said control means to move said plunging member.
The actuating member may comprise a housing whereby the second end of the connector extends slidably through an aperture in the housing and is coupled to an actuator provided in the housing, for example physically or by way of magnetic fields, such that movement of the actuator results in movement of said plunging member away from the body canal to allow at least some fluid flow therethrough. The actuating member preferably comprises a motor operatively coupled to the second end of the connector so that activation of the motor causes the second end of the connector to be axially pulled towards the motor resulting in movement of said plunging member away from the body canal to allow at least some fluid flow therethrough.
A trigger mechanism is preferably provided for activating the motor. The trigger mechanism may be a magnetically operated switch, a radio-controlled circuit, a manually operated button implanted under the patient""s skin, or any other suitable trigger mechanism. A manual override system may also be included. The manual override system may include a magnet that can be used outside the patient""s body.
A second aspect of the invention provides an implantable apparatus for controlling fluid flow within a host body comprising a constricting member for restricting fluid flow within a body canal when in a closed position, and for allowing fluid flow within the body canal when in an open position; a control mechanism for controlling movement of the constricting member between said open and closed positions; and a link member linking the constricting member and the control mechanism such that the constricting member and the control mechanism are implantable in different parts of the host body.
The control mechanism can be separable from said link member so that said control mechanism may be replaced without removal of the constricting member or the link member from the host body.
Preferably, the link member is adapted for moving said constricting member between said open and closed positions so as to alter fluid flow within the body canal, and an actuating member is preferably provided for actuating said link member. The link member may be a cable provided in a protective sleeve, or may be any other suitable link between the constricting member and the control member such as a wire carrying electronic control signals, a wireless radio communication system, etc.
The actuating member and the control mechanism are preferably provided in a housing separate from the constricting member. The actuating member is preferably a motor, most preferably with a remotely operated trigger mechanism, for example, a magnetically operated trigger mechanism, for activating the motor or magnetic unit from a position outside the patient""s body.
The motor or magnetic unit preferably acts through a worm gear. Preferably, the worm gear defines an axis, and the link member is attached to a casing, the worm gear co-operating with a threaded aperture provided in said casing in order to move said casing in a direction parallel to the axis of the worm gear.
According to another aspect of the present invention, there is provided a seal for an elongated link member, the link member extending between an implantable apparatus for implantation in a host body and a control mechanism. The link member extends through an opening in a housing. The seal includes a tubular membrane having two openings, one opening being sealed to the housing, the other opening being sealed to the link member such that fluid entering the housing around the link member is trapped by the membrane. The membrane flexes to allow movement of the shaft.
The membrane is preferably sealed to said link member by gripping means extending around the membrane and the shaft. The gripping means may comprise a coil. The membrane preferably comprises a bellows that folds inwardly when the link member is moved axially away from an interior of the housing, and expands when the link member is moved axially into the housing. The bellows may include a reinforcing ring so that folding of the bellows may be controlled.
According to yet another aspect of the invention, there is provided an operating mechanism for a constricting member for controlling fluid flow in a body canal. The constricting member is actuable between open and closed positions. The operating mechanism includes an axially moveable link member operatively connected to the constricting member for actuating the constricting member. Operating means are provided for axially moving the link member. A coupling for selectively transmitting the axial movement is connected between the link member and the operating means.
The coupling acts so that in one direction there is positive engagement between the operating means and the link member, whereas in an other direction, some play is allowed between the operating means and the link member. The coupling may be used so that opening of the body canal may be achieved by direct actuation of the operating means acting on the link member, but on closing of the body canal, the coupling prevents pressure being directly applied to the body canal by the operating means, thus reducing the likelihood of damage to the body canal.
The coupling may include magnets or a compressible member. A magnet may be attached to the link member, and at least one other magnet may be attached to the operating means. The magnets may be physically moveable towards and away from each other, or they may be electromagnets such that they may be operated when required. The compressible member may be provided in a moveable casing. The link member may be operatively connected to the compressible member, the motor acting to move the casing, and the compressible member acting to move the link member. Alternatively, the coupling may include chain links or a jointed extensible framework, or other means of preventing direct application of pressure to the body canal.
In the case of a coupling comprising magnets, a manual override system may be included, which manual override system comprises a further magnet operable from outside the patient""s body. The manual override magnet should be of sufficient strength to move the magnet attached to the link member against the magnetic force of the magnet attached to the operating means.
Another aspect of the invention provides a method of controlling fluid flow within a host body. The method includes implanting a constricting member around a body canal, the constricting member reducing fluid flow in the body vessel when in a closed position. The method further includes implanting a control mechanism in the host body; and providing and implanting a link member between the constricting member and the control mechanism to allow the control mechanism to control the constricting member. The control mechanism may be removed from the host body and replaced without removal of the constricting member and the linking member.
The constricting member may include engaging elements defining an opening therebetween, the method including surrounding the body canal with the engaging elements so that the body canal extends through the opening.
The method may further include suturing the engaging elements to the vessel. In addition, the control mechanism may be implanted remote from the body canal.
Yet a further aspect of the invention includes a remote telemetry system for an implantable apparatus, the telemetry system including a signaling mechanism capable of sending and receiving signals to and from a control unit implanted in a host body in order to monitor the operation of the implantable apparatus, the telemetry system being capable of altering operating settings of the implantable apparatus.
The signals are preferably electromagnetic radiation, most preferably radio signals. The implantable apparatus may include sensors to monitor actions of the implantable apparatus on the host body, and the telemetry system would include a mechanism to interrogate the sensors to provide feedback on the sensed data. Preferably, the sensors are capable of monitoring pressure exerted by a moveable part of the implantable apparatus on a part of the host body, the feedback on the sensed data including commands to alter the range of movement of the moveable part of the implantable apparatus.
Another aspect of the invention includes an implantable apparatus for controlling fluid flow in a host body. The implantable apparatus includes a constricting mechanism including a reciprocable member for selectively applying pressure to a canal of the host body in order to selectively constrict the canal. A pressure sensor is included for detecting the pressure applied by the reciprocable member to the canal. A feedback system is also included for altering movement of said reciprocable member in response to the pressure sensed by said pressure sensor in order to prevent damage to said canal.
The object and advantages of the implantable fluid flow control devices of the present invention permit implantation and use without severing the canal or vessel to be constricted. Moreover, because trauma is minimized with respect to the canal or vessel, and the devices of the present invention are relatively small, lightweight and made of corrosion-resistant material, such as durable plastics, titanium or stainless steel, the devices are suitable for use for extended periods of time to control fluid flow through numerous types of vessels to control, for example, urination, defecation, ejaculation, nutrition absorption for control of obesity, etc. Splitting the fluid flow control device and its control box also provides significant advantages. The surgery to implant the fluid flow control device is delicate and involved, whereas the surgery to implant the control box is much less involved as the control box may be implanted in an easily accessible place, just under the skin of the patient. Thus, when any part of the control box fails, the control box may be removed and replaced with a new control box without needing to adjust the fluid flow control device. The replacement of the control box does not therefore need to be done by a specialist surgeon, and may be performed in a large number of hospitals or even physicians offices under local anaesthetic. The surgery is thus much less traumatic for the patient and may be performed in a location that is convenient for the patient rather than in a hospital that is able to perform specialized urological surgeries.
These and other objects, features and advantages of the present invention may be better understood and appreciated from the following detailed description of the embodiments thereof, selected for purposes of illustration and shown in the accompany drawings. It should therefore be understood that the particular embodiments illustrating the present invention are exemplary only and not to be regarded as limitations of the present invention. In particular, the illustrated embodiment relates to an artificial sphincter for a urethra, but it should be understood that the device can be used with any body fluid flow canal or vessel.